Maximum Sum-Rate of MIMO Multiuser Scheduling with Linear Receivers

TL;DR

This paper provides a comprehensive analysis of maximum sum-rate in multiuser MIMO systems with linear receivers, considering both no feedback and limited feedback scenarios, and deriving new exact, approximate, and scaling results.

Contribution

It introduces new exact and approximate sum-rate formulas for MRC, ZF, and MMSE receivers under various SNR regimes and feedback conditions.

Findings

Sum-rate results for MRC and MMSE at high SNR

Approximate sum-rate formulas for limited feedback

Sum-rate convergence for large user numbers

Abstract

We analyze scheduling algorithms for multiuser communication systems with users having multiple antennas and linear receivers. When there is no feedback of channel information, we consider a common round robin scheduling algorithm, and derive new exact and high signal-to-noise ratio (SNR) maximum sum-rate results for the maximum ratio combining (MRC) and minimum mean squared error (MMSE) receivers. We also present new analysis of MRC, zero forcing (ZF) and MMSE receivers in the low SNR regime. When there are limited feedback capabilities in the system, we consider a common practical scheduling scheme based on signal-to-interference-and-noise ratio (SINR) feedback at the transmitter. We derive new accurate approximations for the maximum sum-rate, for the cases of MRC, ZF and MMSE receivers. We also derive maximum sum-rate scaling laws, which reveal that the maximum sum-rate of all three linear receivers converge to the same value for a large number of users, but at different rates.